1.soak the sealing ring in the oil, so that it can increase the lubricating property. 2.sealing ring one by one step by step, do not look at the whole set, to keep the sealing ring in order to regulate. 3.seal must have set into the cylinder, revealing only the screws tightened again, otherwise difficult to fit into the inside of the cylinder liner is easy to install sealing ring badly, the impact of the life. 4. before installing the test machine, please go ahead to the machine to add 8--10 drops of oil! Ensure that the sealing ring is used for a long time. Size:12mm-27mm Suitable For: 390, 395, 490, 495, 595 colour:White + black Material:rubber Package Contents: 1 set * sprayer seals Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.